Posts filed under ‘Desinfection and Sterilization’

Still fighting prosthetic joint infection after knee replacement

LANCET Infectous Diseases June 2019 V.19 N.6

COMMENT – Still fighting prosthetic joint infection after knee replacement

We congratulate Erik Lenguerrand and colleagues on the publication of their paper in The Lancet Infectious Diseases1 and respect that it is a well-conducted study. In their large-scale observational study, the authors collected data from the UK National Joint Registry including a total of 679 010 primary knee arthroplasty cases and evaluated associations between patient, surgical, and healthcare system factors and the risk of revision for prosthetic joint infection. To the best of our knowledge, this is the largest cohort study to date analysing the risk factors for periprosthetic joint infection following primary total knee replacement…





LANCET Infectous Diseases June 2019 V.19 N.6

Risk factors associated with revision for prosthetic joint infection following knee replacement: an observational cohort study from England and Wales


Prosthetic joint infection is a devastating complication of knee replacement. The risk of developing a prosthetic joint infection is affected by patient, surgical, and health-care system factors. Existing evidence is limited by heterogeneity in populations studied, short follow-up, inadequate power, and does not differentiate early prosthetic joint infection, most likely related to the intervention, from late infection, more likely to occur due to haematogenous bacterial spread. We aimed to assess the overall and time-specific associations of these factors with the risk of revision due to prosthetic joint infection following primary knee replacement.


In this cohort study, we analysed primary knee replacements done between 2003 and 2013 in England and Wales and the procedures subsequently revised for prosthetic joint infection between 2003 and 2014. Data were obtained from the National Joint Registry linked to the Hospital Episode Statistics data in England and the Patient Episode Database for Wales. Each primary replacement was followed for a minimum of 12 months until the end of the observation period (Dec 31, 2014) or until the date of revision for prosthetic joint infection, revision for another indication, or death (whichever occurred first). We analysed the data using Poisson and piecewise exponential multilevel models to assess the associations between patient, surgical, and health-care system factors and risk of revision for prosthetic joint infection.


Of 679 010 primary knee replacements done between 2003 and 2013 in England and Wales, 3659 were subsequently revised for an indication of prosthetic joint infection between 2003 and 2014, after a median follow-up of 4·6 years (IQR 2·6–6·9). Male sex (rate ratio [RR] for male vs female patients 1·8 [95% CI 1·7–2·0]), younger age (RR for age ≥80 years vs <60 years 0·5 [0·4–0·6]), higher American Society of Anaesthesiologists [ASA] grade (RR for ASA grade 3–5 vs 1, 1·8 [1·6–2·1]), elevated body-mass index (BMI; RR for BMI ≥30 kg/m2 vs <25 kg/m2 1·5 [1·3–1·6]), chronic pulmonary disease (RR 1·2 [1·1–1·3]), diabetes (RR 1·4 [1·2–1·5]), liver disease (RR 2·2 [1·6–2·9]), connective tissue and rheumatic diseases (RR 1·5 [1·3–1·7]), peripheral vascular disease (RR 1·4 [1·1–1·7]), surgery for trauma (RR 1·9 [1·4–2·6]), previous septic arthritis (RR 4·9 [2·7–7·6]) or inflammatory arthropathy (RR 1·4 [1·2–1·7]), operation under general anaesthesia (RR 1·1 [1·0–1·2]), requirement for tibial bone graft (RR 2·0 [1·3–2·7]), use of posterior stabilised fixed bearing prostheses (RR for posterior stabilised fixed bearing prostheses vs unconstrained fixed bearing prostheses 1·4 [1·3–1·5]) or constrained condylar prostheses (3·5 [2·5–4·7]) were associated with a higher risk of revision for prosthetic joint infection. However, uncemented total, patellofemoral, or unicondylar knee replacement (RR for uncemented vs cemented total knee replacement 0·7 [95% CI 0·6–0·8], RR for patellofemoral vs cemented total knee replacement 0·3 [0·2–0·5], and RR for unicondylar vs cemented total knee replacement 0·5 [0·5–0·6]) were associated with lower risk of revision for prosthetic joint infection. Most of these factors had time-specific effects, depending on the time period post-surgery.


We have identified several risk factors for revision for prosthetic joint infection following knee replacement. Some of these factors are modifiable, and the use of targeted interventions or strategies could lead to a reduced risk of revision for prosthetic joint infection. Non-modifiable factors and the time-specific nature of the effects we have observed will allow clinicians to appropriately counsel patients preoperatively and tailor follow-up regimens.


National Institute for Health Research.

FULL TEXT 2/fulltext?dgcid=raven_jbs_etoc_email



May 24, 2019 at 7:39 am

The prevention of Prosthetic Joint Infection (PJI)- 12 modifiable risk factors

The Bone & Joint Journal January 2019 V.101-B N.1 Suppl.A P.3-9

K. Alamanda, B. D. Springer


Prosthetic joint infection (PJI) remains a serious complication that is associated with high morbidity and costs. The aim of this study was to prepare a systematic review to examine patient-related and perioperative risk factors that can be modified in an attempt to reduce the rate of PJI.

Materials and Methods

A search of PubMed and MEDLINE was conducted for articles published between January 1990 and February 2018 with a combination of search terms to identify studies that dealt with modifiable risk factors for reducing the rate of PJI. An evidence-based review was performed on 12 specific risk factors: glycaemic control, obesity, malnutrition, smoking, vitamin D levels, preoperative Staphylococcus aureus screening, the management of anti-rheumatic medication, perioperative antibiotic prophylaxis, presurgical skin preparation, the operating room environment, irrigant options, and anticoagulation.


Poor glycaemic control, obesity, malnutrition, and smoking are all associated with increased rates of PJI. Vitamin D replacement has been shown in preliminary animal studies to decrease rates of PJI. Preoperative Staphylococcus aureus screening and appropriate treatment results in decreased rates of PJI. Perioperative variables, such as timely and appropriate dosage of prophylactic antibiotics, skin preparation with chlorohexidine-based solution, and irrigation with dilute betadine at the conclusion of the operation, have all been associated with reduced rates of PJI. Similarly, aggressive anticoagulation and increased operating room traffic should be avoided to help minimize risk of PJI.


PJI remains a serious complication of arthroplasty. Surgeons should be vigilant of the modifiable risk factors that can be addressed in an attempt to reduce the risk of PJI.




January 20, 2019 at 11:06 am

Healthcare-associated infections: bacteriological characterization of the hospital surfaces in the University Hospital of Abomey-Calavi/so-ava in South Benin (West Africa).

BMC Infect Dis. January 7, 2019 V.19 N.1 P.28.                   


Afle FCD1, Agbankpe AJ2, Johnson RC3, Houngbégnon O4, Houssou SC5, Bankole HS4.

Author information

1 Interfaculty Center of Training and Research in Environment for Sustainable Development, University of Abomey-Calavi, 01, PO, Box 1463, Cotonou, Benin.

2 Research Unit in Applied Microbiology and Pharmacology of Natural Substances, Research Laboratory in Applied Biology, Polytechnic School of Abomey-Calavi University, University of Abomey-Calavi, 01, PO, Box 2009, Cotonou, Benin.

3 Interfaculty Center of Training and Research in Environment for Sustainable Development, University of Abomey-Calavi, 01, PO, Box 1463, Cotonou, Benin.

4 Bacteriology Laboratory of the Ministry of Public Health, 01, PO, Box 418, Cotonou, Benin.

5 Faculty of Human Sciences, University of Abomey Calavi, Cotonou, Benin.



Healthcare-associated infections have become a public health problem, creating a new burden on medical care in hospitals. The emergence of multidrug-resistant bacteria poses a difficult task for physicians, who have limited therapeutic options. The dissemination of pathogens depends on “reservoirs”, the different transmission pathways of the infectious agents and the factors favouring them. Contaminated environmental surfaces are an important potential reservoir for the transmission of many healthcare-associated pathogens. Pathogens can survive or persist in the environment for months and be a source of infection transmission when appropriate hygiene and disinfection procedures are inefficient. The aim of this study was to identify bacterial species from hospital surfaces in order to effectively prevent healthcare-associated infections.


Samples were taken from surfaces at the University Hospital of Abomey-Calavi/So-Ava in South Benin (West Africa). To achieve the objective of this study, 160 swab samples of hospital surfaces were taken as recommended by the International Organization for Standardization (ISO 14698-1). These samples were analysed in the bacteriology section of the National Laboratory for Biomedical Analysis. All statistical analyses were performed using SPSS Statistics 21 software. A Chi Square Test was used to test the association between the Results of culture samples and different care units.


Of the 160 surface samples, 65% were positive for bacteria. The frequency of isolation was predominant in Paediatrics (87.5%). The positive samples were 64.2% Gram-positive bacteria and 35.8% of Gram-negative bacteria. Staphylococcus aureus predominated (27.3%), followed by Bacillus spp. (23.3%). The proportion of other microorganisms was negligible. S. aureus and Staphylococcus spp. were present in all care units. There was a statistically significant association between the Results of culture samples and different care units (χ2 = 12.732; p = 0.048).


The bacteria found on the surfaces of the University Hospital of Abomey-Calavi/So-Ava’s care environment suggest a risk of healthcare-associated infections. Adequate hospital hygiene measures are required. Patient safety in this environment must become a training priority for all caregivers.



January 11, 2019 at 8:46 am

Molecular analysis of bacterial contamination on stethoscopes in an intensive care unit

Infect Control Hosp Epidemiol. December 12, 2018


Culture-based studies, which focus on individual organisms, have implicated stethoscopes as potential vectors of nosocomial bacterial transmission. However, the full bacterial communities that contaminate in-use stethoscopes have not been investigated.


We used bacterial 16S rRNA gene deep-sequencing, analysis, and quantification to profile entire bacterial populations on stethoscopes in use in an intensive care unit (ICU), including practitioner stethoscopes, individual-use patient-room stethoscopes, and clean unused individual-use stethoscopes. Two additional sets of practitioner stethoscopes were sampled before and after cleaning using standardized or practitioner-preferred methods.


Bacterial contamination levels were highest on practitioner stethoscopes, followed by patient-room stethoscopes, whereas clean stethoscopes were indistinguishable from background controls. Bacterial communities on stethoscopes were complex, and community analysis by weighted UniFrac showed that physician and patient-room stethoscopes were indistinguishable and significantly different from clean stethoscopes and background controls. Genera relevant to healthcare-associated infections (HAIs) were common on practitioner stethoscopes, among which Staphylococcus was ubiquitous and had the highest relative abundance (6.8%–14% of contaminating bacterial sequences). Other HAI-related genera were also widespread although lower in abundance. Cleaning of practitioner stethoscopes resulted in a significant reduction in bacterial contamination levels, but these levels reached those of clean stethoscopes in only a few cases with either standardized or practitioner-preferred methods, and bacterial community composition did not significantly change.


Stethoscopes used in an ICU carry bacterial DNA reflecting complex microbial communities that include nosocomially important taxa. Commonly used cleaning practices reduce contamination but are only partially successful at modifying or eliminating these communities.


December 31, 2018 at 1:03 pm

High-risk Staphylococcus aureus transmission in the operating room: A call for widespread improvements in perioperative hand hygiene and patient decolonization practices

American Journal of Infection Control October 2018 V.46 N.10 P.1134–1141

Randy W. Loftus, Franklin Dexter, Alysha D.M. Robinson


  • Intraoperative Staphylococcus aureus multilocus sequence type 5 is hypertransmissible and pathogenic.
  • Intraoperative provider hands and patient skin surfaces are confirmed sources of sequence type 5 transmission.


Increased awareness of the epidemiology of transmission of pathogenic bacterial strain characteristics may help to improve compliance with intraoperative infection control measures. Our aim was to characterize the epidemiology of intraoperative transmission of high-risk Staphylococcus aureus sequence types (STs).


S aureus isolates collected from 3 academic medical centers underwent whole cell genome analysis, analytical profile indexing, and biofilm absorbance. Transmission dynamics for hypertransmissible, strong biofilm-forming, antibiotic-resistant, and virulent STs were assessed.


S aureus ST 5 was associated with increased risk of transmission (adjusted incidence risk ratio, 6.67; 95% confidence interval [CI], 1.82-24.41; P?=?.0008), greater biofilm absorbance (ST 5 median absorbance ± SD, 3.08 ± 0.642 vs other ST median absorbance ± SD, 2.38 ± 1.01; corrected P?=?.021), multidrug resistance (odds ratio, 7.82; 95% CI, 2.19-27.95; P?=?.002), and infection (6/38 ST 5 vs 6/140 STs; relative risk, 3.68; 95% CI, 1.26-10.78; P?=?.022). Provider hands (n?=?3) and patients (n?=?4) were confirmed sources of ST 5 transmission. Transmission locations included provider hands (n?=?3), patient skin sites (n?=?4), and environmental surfaces (n?=?2). All observed transmission stories involved the within-case mode of transmission. Two of the ST 5 transmission events were directly linked to infection.


Intraoperative S aureus ST 5 isolates are hypertransmissible and pathogenic. Improved compliance with hand hygiene and patient decolonization may help to control the spread of these dangerous pathogens.



December 3, 2018 at 7:40 am

Improving the Diagnosis of Orthopedic Implant-Associated Infections: Optimizing the Use of Tools Already in the Box

Clin. Microbiol. December 2018 V.56 N.12

Shawn Vasoo

With the increasing number of prosthetic joints replaced annually worldwide, orthopedic implant-associated infections (OIAI) present a considerable burden. Accurate diagnostics are required to optimize surgical and antimicrobial therapy. Sonication fluid cultures have been shown in multiple studies to improve the microbiological yield of OIAIs, but uptake of sonication has not been widespread in many routine clinical microbiology laboratories. In this issue, M. Dudareva and colleagues (J Clin Microbiol 56:e00688-18, 2018, describe their unit’s experience with OIAI diagnosis using periprosthetic tissue inoculated into an automated blood culture system and sonication fluid culture.





Clin. Microbiol. December 2018 V.56 N.12

Sonication versus Tissue Sampling for Diagnosis of Prosthetic Joint and Other Orthopedic Device-Related Infections

Maria Dudareva, Lucinda Barrett, Mel Figtree, Matthew Scarborough, Masanori Watanabe, Robert Newnham, Rachael Wallis, Sarah Oakley, Ben Kendrick, David Stubbs, Martin A. McNally, Philip Bejon, Bridget A. Atkins, Adrian Taylor and Andrew J. Brent

Current guidelines recommend collection of multiple tissue samples for diagnosis of prosthetic joint infections (PJI). Sonication of explanted devices has been proposed as a potentially simpler alternative; however, reported microbiological yield varies. We evaluated sonication for diagnosis of PJI and other orthopedic device-related infections (DRI) at the Oxford Bone Infection Unit between October 2012 and August 2016. We compared the performance of paired tissue and sonication cultures against a “gold standard” of published clinical and composite clinical and microbiological definitions of infection. We analyzed explanted devices and a median of five tissue specimens from 505 procedures. Among clinically infected cases the sensitivity of tissue and sonication culture was 69% (95% confidence interval, 63 to 75) and 57% (50 to 63), respectively (P < 0.0001). Tissue culture was more sensitive than sonication for both PJI and other DRI, irrespective of the infection definition used. Tissue culture yield was higher for all subgroups except less virulent infections, among which tissue and sonication culture yield were similar. The combined sensitivity of tissue and sonication culture was 76% (70 to 81) and increased with the number of tissue specimens obtained. Tissue culture specificity was 97% (94 to 99), compared with 94% (90 to 97) for sonication (P = 0.052) and 93% (89 to 96) for the two methods combined. Tissue culture is more sensitive and may be more specific than sonication for diagnosis of orthopedic DRI in our setting. Variable methodology and case mix may explain reported differences between centers in the relative yield of tissue and sonication culture. Culture yield was highest for both methods combined.



November 28, 2018 at 3:12 pm


Medicina (B Aires). 2018;78(2):99-106.

Pneumonia associated with mechanical ventilation. Update and recommendations inter- Societies SADI-SATI.

[Article in Spanish]

Cornistein W1, Colque ÁM2, Staneloni MI3, Monserrat Lloria M4, Lares M5, González AL5, Fernández Garcés A6, Carbone E7.

Author information

1 Hospital General de Agudos Dr. Cosme Argerich, Hospital Universitario Austral, Buenos Aires, Argentina. E-mail:

2 Complejo Médico Churruca Visca, Buenos Aires, Argentina.

3 Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.

4 Hospital Prof. Alejandro Posadas, Buenos Aires, Argentina.

5 Hospital Interzonal General de Agudos San Martín de La Plata, Argentina.

6 Clínica AMEBPBA (Mutual de Empleados del Banco de la Provincia de Buenos Aires), Argentina.

7 Hospital Aeronáutico Central, Buenos Aires, Argentina.


Representatives of the Argentine Society of Infectious Diseases (SADI) and the Argentine Society of Intensive Therapy (SATI) worked together on the development of specific recommendations for the diagnosis, treatment and prevention of ventilator-associated pneumonia (VAP). The methodology used was the analysis of the literature published in the last 15 years, complemented with the opinion of experts and local data. This document aims to offer basic tools to optimize diagnosis based on clinical and microbiological criteria, orientation in empirical and targeted antibiotic schemes, news on posology and administration of antibiotics in critical patients and to promote effective measures to reduce the risk of VAP. It also offers a diagnostic and treatment algorithm and considerations on inhaled antibiotics. The joint work of both societies -infectious diseases and intensive care- highlights the concern for the management of VAP and the importance of ensuring improvement in daily practices. This guideline established recommendations to optimize the diagnosis, treatment and prevention of VAP in order to reduce morbidity and mortality, days of hospitalization, costs and resistance to antibiotics due to misuse of antimicrobials.


November 3, 2018 at 10:43 am

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